Tailored surgical strategies for anterior cruciate ligament (ACL) reconstruction in skeletally immature patients are presented, emphasizing techniques to minimize growth plate damage and ensure stability. As ACL injuries in youth increase, delaying surgery can lead to joint damage and poor recovery outcomes. Using magnetic resonance imaging-based assessments of skeletal maturity, the authors propose the 'over-the-top (OTT)' approach with lateral tenodesis, adapted for three growth stages: prepubescents, young adolescents and older adolescents. For prepubescents, the extra-physeal approach avoids growth plate drilling; for young adolescents, the supra-physeal technique places tunnels above the growth plate; and for older adolescents, the trans-physeal method mirrors adult techniques, as growth plates are closing. The minimally invasive OTT technique preserves hamstring insertion, ensures isometric graft placement, and allows for combined intra- and extra-articular procedures to improve rotational control and protect the graft. Clinical outcomes highlight high return-to-sport rates, minimal growth disturbances, and low failure rates, although older adolescents show higher graft failures due to activity levels. Various adaptations of the OTT and lateral tenodesis techniques utilizing hamstring tendons provide promising solutions for addressing ACL injuries in skeletally immature patients, ranging from prepubescence to late adolescence. Assessing skeletal age and estimating remaining bone growth are essential for selecting the most appropriate surgical method. The biomechanical principles and positive clinical results observed across different patient groups highlight these techniques as effective, safe and attractive options for managing these challenging cases. LEVEL OF EVIDENCE: Level IV.

Objectives: The addition of a lateral extra-articular tenodesis (LET) at the time of anterior cruciate ligament reconstruction (ACLR) is known to reduce ACL graft forces. Accordingly, LET has been shown to lower the risk of ACL graft rupture in patients who are high risk due to young age, elevated tibial slope, high grade laxity, and participation in pivoting sports. However, it is unknown whether the effectiveness of LET in patients with increasing posterior tibial slope (PTS) may plateau or drop-off at a threshold slope value. Although ACL graft force increases with increasing slope without an LET, the relationship between ACL graft force and tibial slope with an LET is less well understood. Therefore, the objective of this study was to evaluate how increasing posterior tibial slope alters the protective effect of a lateral extra-articular tenodesis on ACL graft force during pivot and anterior drawer. Methods: Eighteen finite element knee models representing the intact ACL, ACLR, and ACLR with LET conditions at six levels of PTS ranging from 0 º to 20º were derived from a single cadaveric specimen. Computed tomography scans, experimentally measured envelope of motion, and manually digitized soft-tissue attachments were collected to personalize the models. Rotational knee laxity was equalized across all slope-adjusted intact ACL knee models utilizing a computational soft-tissue calibration procedure which best matched simulated and experimental internal/external and varus/valgus laxities. All ligament and graft materials were modeled as either single or multi-bundle nonlinear springs. A simulated pivot shift was performed on 1) ACLR and 2) ACLR with LET models by applying 5 N·m valgus and 3 N·m internal rotation moments to the proximal tibia at 30° flexion (Fig.1). Additionally, a modified anterior drawer was simulated with a 710 N compressive force and an anterior force on the tibia, loading the ACL graft to 75% of its tensile failure limit. ACLR and LET forces were recorded for each slope condition. Results: During pivot shift, the addition of a LET decreased forces on the ACL graft at all tibial slopes, with the protective effect increasing as the PTS increased (Fig.2). Increasing PTS from 0° to 20° resulted in an increase in ACL graft forces from 101.3N to 166.1N while LET force increased from 18.0% to 60.4% of ACLR graft force. Comparing ACLR with and without LET, the protective effect of LET increased with tibial slope, from 11.2% to 41.3%, averaging 24.1 ± 10.0%. The protective effect during anterior drawer was approximately constant at 3.0 ± 0.6% across all tibial slopes. Conclusions: LET decreased forces on the ACL graft at all tibial slopes, with its protective effect increasing as the PTS increased in pivot shift, suggesting that orthopaedic surgeons should consider addition of a LET in patients with increased posterior tibial slope.

Purpose: To assess the effect of preoperative and surgical factors on return to play (RTP) rates and career longevity of professional rugby athletes after primary anterior cruciate ligament (ACL) reconstruction (ACL-R). Methods: A retrospective review of a consecutive cohort of professional rugby players undergoing primary ACL-R by the senior author between 2005 and 2019 was undertaken. Athletes were included if they were under contract with a professional rugby team at the time of injury and had a minimum of 2-year follow-up. Univariate and multivariate analyses were performed to determine significant predictors of RTP rate, time and career longevity. Results: One hundred and eighteen rugby players with 125 ACL-Rs were identified. Return to professional rugby was achieved in 115/125 (92%) of cases at an average of 9.6 months and those athletes participated at the professional level for 5.9 +/- 3.4 years after ACL-R. Younger age (p = 0.006) and ACL-R with a concomitant lateral extra-articular tenodesis (LET) (p = 0.013) were predictors of a longer career. A Cox proportional hazards model that controlled for age revealed that athletes who underwent ACL-R with an LET had increased career longevity compared to those with an ACL-R without LET (hazard ratio = 2.74, p = 0.021). No factors were significantly associated with RTP rate or RTP time. Conclusion: In professional rugby players undergoing primary ACL-R, those having ACL-R with a concomitant LET and younger age predicted increased career longevity. Rugby players who underwent LET at the time of ACL-R had an 18% greater chance of still playing professionally at 5 years compared to those who underwent ACL-R alone.

BACKGROUND:Limited data are available regarding career length and competition level after combined anterior cruciate ligament (ACL) and medial- or lateral-sided surgeries in elite athletes. PURPOSE:To evaluate career length after surgical treatment of combined ACL plus medial collateral ligament (MCL) and ACL plus posterolateral corner (PLC) injuries in elite athletes and, in a subgroup analysis of male professional soccer players, to compare career length and competition level after combined ACL+MCL or ACL+PLC surgeries with a cohort who underwent isolated ACL reconstruction (ACLR). STUDY DESIGN:Cohort study; Level of evidence, 3. METHODS:A consecutive cohort of elite athletes undergoing combined ACL+MCL and ACL+PLC surgery was analyzed between February 2001 and October 2019. A subgroup of male elite soccer players from this population was compared with a previously identified cohort having had isolated primary ACLR without other ligament surgery. A minimum 2-year follow-up was required. Outcome measures were career length and competition level. RESULTS:A total of 98 elite athletes met the inclusion criteria, comprising 50 ACL+PLC and 48 ACL+MCL surgeries. The mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Return-to-play (RTP) time was significantly longer for ACL+PLC injuries (12.8 months; P = .019) than for ACL+MCL injuries (10.9 months). In the subgroup analysis of soccer players, a significantly lower number of players with combined ACL+PLC surgery were able to RTP (88%; P = .003) compared with 100% for ACL+MCL surgery and 97% for isolated ACLR, as well as requiring an almost 3 months longer RTP timeline (12.9 months; P = .002) when compared with the isolated ACL (10.2 months) and combined ACL+MCL (10.0 months) groups. However, career length and competition level were not significantly different between groups. CONCLUSION:Among elite athletes, the mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Professional soccer players with combined ACL+PLC surgery returned at a lower rate and required a longer RTP time when compared with the players with isolated ACL or combined ACL+MCL injuries. However, those who did RTP had the same career longevity and competition level.

BACKGROUND:Because of the multitude of variables that affect the retirement decisions of professional soccer players, it has proven difficult to isolate the effect of undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) on career longevity.PURPOSE:To compare the career longevity of professional soccer players after a primary ACLR with that of an uninjured matched control cohort.STUDY DESIGN:Cohort study; Level of evidence, 3.METHODS:A retrospective review of a consecutive series of primary ACLR was performed between 2008 and 2018 in professional male soccer players from the senior author's practice. Each athlete with ACLR was matched to 3 control athletes who had not undergone ACLR according to age, league, playing position, and preinjury game appearances/minutes played. Player career statistics-including league, game appearances, and game minutes-were compiled for each year until retirement or July 1, 2022.RESULTS:A total of 82 soccer players in the English Premier League or Championship at the time of their primary ACLR were matched to 246 control athletes. The mean career length after ACLR was 6 ± 2.6 years, while that of the matched control athletes was 7.6 ± 2.8 years (P < .001). After primary ACLR, an athlete had a 2 times greater chance of retirement compared with the matched control athlete (hazard ratio, 2.19; P < .001). At 5 years after ACLR, 16% of athletes had retired from professional soccer, while 8.5% of the matched cohort were retired (P = .060). By 10 years, 72% of the ACLR cohort had retired compared with 43% of the matched cohort (P < .001). Forwards were more likely to have shortened careers compared with goalkeepers (P = .021); however, no significant differences were observed between midfielders, defenders, and forwards. Within the ACLR cohort, a contralateral ACL tear during the athlete's career caused a 2.30 times (P = .022) increased chance of retirement compared with athletes with only 1 ACL tear during their career. Mechanism of injury, meniscal pathology, graft rerupture, and chondral lesions did not affect career length.CONCLUSION:Professional male soccer players who underwent ACLR had decreased career length by approximately 1.6 years compared with a matched player cohort.

Introduction Reverse shoulder arthroplasty (RSA) is a viable option for proximal humerus fractures (PHFs) in the elderly and cemented humeral fixation is the standard of care. This study evaluates the influence of a diaphyseal press fit stem with a 142o humeral inclination on tuberosity healing (TH) and functional outcome in RSA for PHF. Methods Twenty-three patients received a RSA for PHF by a single surgeon at one center over a 2 year period. The humeral stem design was intended for diaphyseal press fit with a 142o humeral inclination. The tuberosities were repaired for each patient with bone graft and a standard suture technique. Patient clinical and radiographic outcomes were collected with a minimum 12 month follow-up. Results Nineteen of 23 patients (83%) with a mean age of 75 + years were available for follow-up at an average of 14 months. Radiographic analysis showed 68% of patients had evidence of TH. Grade 1 scapular notching was found in 32% of patients. There was no implant loosening or subsidence noted. Average range of motion was 163o + 15o degrees of forward flexion, 113o + 24o of abduction, internal rotation to the waist and an average external rotation of 7 + 1.5 as measured by the Constant-Murley score. Average ASES score was 81.8 and average Constant Murley score was 67.9. While not significant, those with TH trended towards better clinical outcomes. There was a 0% revision rate. Conclusion A press fit stem designed for diaphyseal fixation provides consistent reliable results in RSA for PHF. A high percentage of TH was appreciated with a 142o humeral inclination, neutral glenosphere construct and a standardized bone grafting, suture technique. TH is associated with improved patient outcomes.

BACKGROUND:Historical MCL (medial collateral ligament) reconstruction (MCLR) techniques have focused on the superficial MCL (sMCL) to restore valgus stability while frequently ignoring the importance of the deep MCL (dMCL) in controlling tibial external rotation. The recent recognition of the medial ligament complex importance has multiple studies revisiting medial anatomy and questioning contemporary MCLR techniques.PURPOSE:To assess whether (1) an isolated sMCL reconstruction (sMCLR), (2) an isolated dMCL reconstruction (dMCLR), or (3) a novel single-strand short isometric construct (SIC) would restore translational and rotational stability to a knee with a dMCL and sMCL injury.STUDY DESIGN:Controlled laboratory study.METHODS:Biomechanical testing was performed on 14 fresh-frozen cadaveric knee specimens using a custom multiaxial knee activity simulator. The specimens were divided into 2 groups. The first group was tested in 4 states: intact, after sectioning the sMCL and dMCL, isolated sMCLR, and isolated dMCLR. The second group was tested in 3 states: intact, after sectioning the sMCL and dMCL, and after single-strand SIC reconstruction (SICR). In each state, 4 loading conditions were applied at 0°, 20°, 40°, 60°, and 90° of knee flexion: 8-N·m valgus torque, 5-N·m external rotation torque, 90-N anterior drawer, and combined 90-N anterior drawer plus 5-N·m tibial external rotation torque. Anterior translation, valgus rotation, and external rotation of the knee were measured for each state and loading condition using an optical motion capture system.RESULTS:sMCL and dMCL transection resulted in increased laxity for all loading conditions at all flexion angles. Isolated dMCLR restored external rotation stability to intact levels throughout all degrees of flexion, yet valgus stability was restored only at 0° of flexion. Isolated sMCLR restored valgus and external rotation stability at 0°, 20°, and 40° of flexion but not at 60° or 90° of flexion. Single-strand SICR restored valgus and external rotation stability at all flexion angles. In the combined anterior drawer plus external rotation test, isolated dMCL and single-strand SICR restored stability to the intact level at all flexion angles, while the isolated sMCL restored stability at 20° and 40° of flexion but not at 60° or 90° of flexion.CONCLUSION:In the cadaveric model, single-strand SICR restored valgus and rotational stability throughout the range of motion. dMCLR restored rotational stability to the knee throughout the range of motion but did not restore valgus stability. Isolated sMCLR restored external rotation and valgus stability in early flexion.CLINICAL RELEVANCE:In patients with anteromedial rotatory instability in the knee, neither an sMCLR nor a dMCLR is sufficient to restore stability.

Objectives: The past decade has taught the importance of identifying and treating the concomitant injuries that frequently occur at the time of ACL rupture. Failure to do so can result in increased stresses on the ACL graft and subsequently increased risk of failure. While the focus has largely been on the menisci and the anterolateral soft tissues, recent studies have highlighted high frequency at which injuries to the medial structures occur in previously presumed isolated ACL tears and the increased risk of poor outcomes when they are not addressed. Injuries to the medial ligament complex result in valgus and anteromedial rotatory instability (AMRI). Historic MCL reconstruction techniques have focused on the superficial MCL in an effort to restore valgus stability while frequently ignoring the importance of the deep MCL in controlling tibial external rotation. The recent recognition of the importance of the medial ligament complex has led to multiple studies revisiting medial sided anatomy and questioning contemporary MCL reconstruction techniques. The objective of this study is to assess and compare the ability of a contemporary medial collateral ligament (MCL) reconstruction and a deep MCL (dMCL) reconstruction to restore rotational and valgus stability to the knee. Methods: Six pairs fresh-frozen cadaveric knee specimens were included and with intact soft tissue, the distal femur and tibia were potted in PVC pipes to facilitate biomechanical testing using a customized multi-axial knee activity simulator. Four states were tested: 1) intact 2) after sectioning of the sMCL and dMCL, 3) contemporary MCL reconstruction as described by LaPrade et al, and 4) dMCL reconstruction. In each state, the knees were tested under four loading conditions at varying flexion angles (0°, 20°, 40°, 60° and 90°): 8 Nm valgus torque, 5 Nm tibial external rotation torque, 90N anterior drawer, and combined 90 N anterior drawer plus 5 Nm tibial external rotation torque. Results: Transection of the sMCL and dMCL resulted in increased laxity with the application of the valgus torque, external rotation torque, and combined anterior drawer plus external rotation at all flexion angles. dMCL reconstruction restored external rotation stability to intact levels (all p<0.05) throughout all degrees of flexion (Figure 1), yet dMCL reconstruction did not restore valgus stability at any flexion angle (Figure 2). Contemporary MCL reconstruction restored valgus and external rotation stability at 0° and 20° and valgus stability at 40° (p<0.01). In response to a combined anterior drawer plus tibial external rotation, the dMCL restored stability back to the intact level at 20° and improved stability between 40° and 90° flexion (Figures 3 and 4). In contrast, the contemporary MCL reconstruction did not restore stability at any degree of flexion (p>0.05). Conclusions: Deep MCL reconstruction restored rotational stability to the knee throughout range of motion but did not restore valgus stability. The contemporary MCL reconstruction restore stability only near full extension.

Background: The popularization of all-inside (AI) meniscal repair devices has led to a shift away from the historical gold standard of inside-out (IO) meniscal repair without comparative studies to support the change. Purpose: To compare the failure rate and time to failure of AI and IO meniscal repair performed in elite athletes. Study Design: Cohort study; Level of evidence, 3. Methods: A retrospective review was performed of all professional and national- and international-level amateur athletes who underwent meniscal repair, with a minimum of 2-year follow-up between January 2013 and September 2019. Meniscal repair was classified as AI or IO depending on the surgical technique performed. Treatment failure was defined as patients having to undergo subsequent surgery to address a persistent meniscal tear after repair. Cox proportional hazards modeling was used to determine if meniscal repair failure rates differed by the location and technique of meniscal repair. Models were controlled for known risk factors such as age, sex, sport, and concurrent cruciate ligament reconstruction. Results: A total of 192 (135 lateral and 57 medial) meniscal repairs were performed in elite athletes during the study period. Overall, 41 (21%) meniscal repairs met the criteria for failure. Medial meniscal tears repaired with the AI technique failed at a significantly higher rate (18/31 [58%]) than medial meniscal tears repaired with the IO technique (6/26 [23%]) or lateral meniscal tears repaired with the AI (9/76 [12%]) or IO (8/59 [14%]) technique ( P < .001). Cox proportional hazards modeling revealed that a medial meniscal tear repaired with the AI technique had an almost 8 times greater hazard of failure than a lateral meniscal tear repaired with the AI technique ( P < .001). At 1 year postoperatively, 8% of lateral meniscal repairs had failed (regardless of technique), while medial meniscal tears failed at a rate of 16% with the IO technique and 42% with the AI technique. By 2 years, 53% of medial meniscal tears repaired with the AI technique had failed, and by 5 years, 63% had failed. Conclusion: AI repair of medial meniscal tears led to a higher rate of failure than IO repair of medial or lateral meniscal tears in elite athletes. Medial meniscal repair failed at a higher rate than lateral meniscal repair.

AbstractIntroductionThe aim of this study was to determine which factors affect a professional footballer's return to play performance level after ACL reconstruction (ACL-R). Additionally, to report their playing performance at 2 and 5 years post ACL-R compared to their preinjury performance.MethodsA retrospective review of a consecutive series of primary ACL-R undertaken in professional footballers between 2005 and 2019 was undertaken. Performance was determined by the number of minutes played and the league level compared to their pre-injury baseline. Playing time (minutes) was classified as same (within 20%), more, or less playing time for each season compared to the one year prior to surgery.ResultsTwo hundred footballers (mean age 24.1 ± 4.2 years) were included. 194 (97%) returned to professional football.At 2-years after ACL-R 61% of footballers were playing in the same/ higher league, 29% were playing in a lower league and 10% were not playing. At 5-years this was 35%, 37% and 28% respectively.Forty-six percent of footballers were playing the same or more minutes as pre-injury at 2 years post-surgery, 51% were at 3 and 4 years but this reduced to 45% at 5 years.The presence of >50% thickness chondral pathology, ACL-R lacking lateral extra-articular tenodesis and age over 25 years at surgery were all significant risk factors of worse performance rates after ACL-R.ConclusionWhile professional footballers achieved high initial RTP rates after ACL-R, with the majority returning to pre-operative levels of competition, significant decreases in performance rates were noted over time.

AbstractIntroductionHistoric MCL reconstruction techniques focused on the superficial MCL to restore valgus stability while overlooking tibial external rotation and the deep MCL. This study assessed the ability of a contemporary medial collateral ligament (MCL) reconstruction and a deep MCL (dMCL) reconstruction to restore rotational and valgus knee stability.MethodsSix pairs fresh-frozen cadaveric knee specimens with intact soft tissue were tested in four states: 1) intact 2) after sMCL and dMCL sectioning, 3) contemporary MCL reconstruction (LaPrade et al), and 4) dMCL reconstruction. In each state, four loading conditions were applied at varying flexion angles: 8Nm valgus torque, 5Nm tibial external rotation torque, 90N anterior drawer, and combined 90N anterior drawer plus 5Nm tibial external rotation torque.ResultsTransection of the sMCL and dMCL resulted in increased laxity with valgus torque, external rotation torque, and combined anterior drawer plus external rotation. dMCL reconstruction restored external rotation stability to intact levels throughout all degrees of flexion but did not restore valgus stability at any flexion angle. Contemporary MCL reconstruction restored valgus and external rotation stability at 0° and 20° and valgus stability at 40°. In the combined anterior drawer plus tibial external rotation trial, the dMCL restored stability at 20° and improved stability between 40° and 90° flexion. Conversely, the contemporary MCL reconstruction did not restore stability at any degree of flexion.ConclusionDeep MCL reconstruction restored rotational stability to the knee throughout range of motion but not valgus stability. The contemporary MCL reconstruction restored stability only near full extension.

Background: Thigh pain is relatively common after total knee arthroplasty (TKA) and has been attributed to compression of the thigh muscles by the tourniquet used during surgery. Thigh pain that occurs after a TKA that was performed without a tourniquet may be due to a strain of the quadriceps muscle or insertion of the intramedullary (IM) rod. The purpose of the present study was to determine the cause of thigh pain after TKA in a randomized controlled trial evaluating tourniquet use, IM rod use, and quadriceps strain. Methods: This prospective randomized controlled trial enrolled 97 subjects undergoing primary knee arthroplasty into 4 groups according to tourniquet use (yes or no) and IM rod use (yes or no). Quadriceps strain was evaluated with magnetic resonance imaging (MRI) on postoperative day 1 (POD 1). Data collected preoperatively, intraoperatively, and postoperatively until the 6-week clinical visit included pain levels for the knee and thigh (recorded separately) and knee range of motion. Results: Regardless of tourniquet or IM rod use, 73 (75%) of the 97 patients reported thigh pain on POD 1. Thigh pain at 2 weeks postoperatively was indicative of a quadriceps strain. Use of a tourniquet and patient-reported thigh pain at 2 weeks increased the odds of a quadriceps strain, whereas IM rod use did not significantly contribute to thigh pain. Conclusions: The etiology of thigh pain after TKA may be multifactorial; however, an iatrogenic quadriceps strain is one source of thigh pain after TKA, especially if the pain persists 2 weeks after surgery. Level of Evidence: Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence.

T-cell subsets, including naïve (NA), central memory (CM), transitional memory (TM), effector memory (EM), and RA + effector memory (EMRA), differ in phenotype and function. T-cells are mobilized by exercise, with differences in the magnitude of mobilization between subsets. However, the response of TM T-cells to exercise has not yet been described. Further, T-cells expressing the late differentiation marker CD57 are known to be highly responsive to exercise, but the relative response of CD57 + and CD57- within T-cell subsets is unknown. We therefore aimed to characterize the exercise-induced mobilization of TM T-cells, as well as to compare the exercise response of CD57 + and CD57- cells within T-cell subsets.MethodsSeventeen participants (7 female; aged 18–40 years) cycled 30 min at 80% of their estimated maximum heart rate. Venous blood obtained pre, post, and 1H post-exercise was analyzed by flow cytometry. CD45RA, CCR7, and CD28 expression within CD4 + and CD8+ T-cells identified NA, CM, TM, EM, and EMRA subsets. CD57 expression within EM, EMRA, and CD28+ T-cells was also quantified. The relative mobilization of each subset was compared by calculating fold change in cell concentration during (ingress, post/pre) and after exercise (egress,1H post/post). Cytomegalovirus (CMV) serostatus was determined by ELISA and was considered in models.ResultsTM CD8+ T-cell concentration was greater post-exercise than pre-exercise (138.59 ± 56.42 cells/µl vs. 98.51 ± 39.68 cells/µl, p < 0.05), and the proportion of CD8 + with a TM phenotype was elevated 1H post-exercise (1H: 32.44 ± 10.38% vs. Pre: 30.15 ± 8.77%, p < 0.05). The relative mobilization during and after exercise of TM T-cells did not differ from NA and CM but was less than EM and EMRA subsets. Similar results were observed within CD4+ T-cells. CD57 + subsets of CD28+ T-cells and of EM and EMRA CD8+ T-cells exhibited a greater relative mobilization than CD57- subsets (all p < 0.05).ConclusionThese results indicate TM CD4 + and CD8+ T-cells are transiently mobilized into the blood with exercise, but not to as great of an extent as later differentiated EM and EMRA T-cells. Results also indicate CD57 identifies highly exercise responsive cells within CD8+ T-cell subsets.

Background: Major joint/limb reattachment procedures of upper extremities (Diagnosis-related group 483, DRG-483) are increasingly utilized, while average costs have increased yearly. This study seeks to determine the influence of volume, neighborhood demographics, and orthopedic specialization on the cost of DRG-483. Methods: Utilization and cost data for DRG-483 was extracted from Centers for Medicare and Medicaid Services (CMS) inpatient charge data from 2014-2018. Neighborhood demographic data was queried as USDA Rural-Urban Commuting Area codes (RUCA) from the United States 2010 census and Esri’s ArcMap software. Orthopedic specialization ratios for each hospital (OSR = Musculoskeletal discharges/Total Discharges) was utilized to compare Orthopedic Specialty Hospitals (OSH) = OSR>0.99 and Nonspecialty Hospitals (NSH) = OSR≤0.99. The cost of DRG-483 procedures and the influence of volume, hospital demographics, and orthopedic specialization was analyzed using linear regression models. Results: OSH performed DRG-483 procedures at lower average Medicare payments (AMP) than NSH in all years studied ( P <0.001), averaging 15% saved per surgery. DRG-483 volume was weakly negatively correlated with AMP, averaging $2.95 saved per discharge. Finally, population density of hospital location was inversely proportional to DRG-483 AMP with metropolitan centers performing the procedure at the lowest cost to the CMS. Conclusions: CMS payments are optimized at urban orthopedic specialty hospitals. Eliminating the AMP difference for the 222,519 DRG-483 performed at NSH would have saved CMS over 480 million dollars between 2014-2018.

AbstractIntroductionPersistent medial laxity increases the risk of failure for ACL reconstruction. To address this, multiple reconstruction techniques have been created. To date, no single strand reconstruction constructs have been able to restore both valgus and rotational stability. In response to this, a novel single strand Short Isometric Construct (SIC) MCL reconstruction was developed.MethodsEight fresh-frozen cadaveric specimens were tested in three states: 1) intact 2) after sMCL and dMCL transection, and 3) after SIC MCL reconstruction. In each state, four loading conditions were applied at varying flexion angles: 90N anterior drawer, 5Nm tibial external rotation torque, 8Nm valgus torque, and combined 90N anterior drawer plus 5Nm tibial external rotation torque.ResultsTransection of the sMCL and dMCL resulted in increased laxity with external rotation torque, valgus torque, and combined anterior drawer plus external rotation. SIC MCL reconstruction restored external rotation and valgus stability to intact levels throughout all degrees of flexion. In the combined test SIC MCL reconstruction also restored stability to intact levels for both anterior distraction and external rotation throughout the range of motion. No significant differences were noted between intact and SIC reconstruction.ConclusionThe single-limb short isometric construct (SIC) MCL reconstruction restored native valgus and rotatory stability to a sMCL- and dMCL-deficient knee in biomechanical testing.

BACKGROUND:A number of studies have investigated return to play after anterior cruciate ligament reconstruction (ACLR) in professional soccer players, but it is unclear which factors are associated with a return to the preinjury performance and ability to play over time. PURPOSE:To identify factors that contribute to a professional soccer player's return to preinjury performance after ACLR, as well as to report their playing performance at 2 and 5 years after ACLR compared with their preinjury performance. STUDY DESIGN:Case-control study; Level of evidence, 3. METHODS:A consecutive cohort of professional soccer players undergoing primary ACLR were analyzed between 2005 and 2019. A minimum 2-year follow-up was required. The effect of patient, surgical, and postoperative factors on performance rates, defined as a combination of league level and playing time, was evaluated with univariate and multivariate logistic regression models. RESULTS:A total of 200 male professional soccer players were included. When combining league level and playing time, 30% of athletes returned to their preinjury performance at 2 years and 22% at 5 years. However, 53% of athletes returned to their preinjury performance for at least 1 season by year 5. At 2 years, a chondral lesion of grade 3 or 4 decreased the odds of return to preinjury performance (odds ratio [OR], 0.37; P = .010). Athletes receiving an ACLR with the addition of a lateral extra-articular tenodesis procedure were 2.42 times more likely to return to preinjury performance at 2 years than athletes with ACLR alone (P = .004). By 5 years after ACLR, athletes aged ≥25 years at the time of reconstruction were 3 times less likely to be performing at their preinjury performance (OR, 0.32; P < .001), and those with a grade ≥3 chondral lesion were >2 times less likely to be performing at their preinjury performance (OR, 0.43; P = .033). CONCLUSION:The presence of >50% thickness chondral pathology, ACLR without lateral extra-articular tenodesis, and age >25 years at the time of surgery were all significant risk factors of worse performance rates after ACLR. Significant decreases in performance rates were noted at 2 and 5 years postoperatively.

Objectives: While advances in surgical technique have led to high levels of return to play in professional soccer players, little is known about their medium- and long-term career trajectory and performance. Methods: A retrospective review was performed of a consecutive series of primary ACL reconstructions in professional soccer players from the senior author’s practice, with a minimum of two-year follow-up. Clinical and performance measures were evaluated at 2- and 5-years post ACLR to determine pre- operative, operative and post-operative factors that affected player performance- measured by the level of league and number of minutes played. Results: 200 male, soccer players were identified who were playing professionally at the time of their primary ACLR. The average age at the time of their primary ACL reconstruction was 24.1±4.2 years. Additional injuries at the time of ACL rupture included 63 (32%) medial meniscus tears with 42 (67%) repaired, 134 (67%) lateral meniscus tears with 82 (62%) repaired, and 31 (16%) chondral lesions of grade 3 or higher. 194 (97%) athletes returned to play (RTP) at 10.7±3.9 months. Return to play was strictly defined as returning to a professional level. Eighteen (9%) athletes sustained a re-rupture at a median of 11.1 months (IQR 8.6-16.6 months) with 6 occurring pre-RTP and 12 post-RTP, while 52 (26%) sustained a contralateral ACL rupture during their soccer career. At 2 years, performance metrics showed that 59% of athletes were playing in the same or higher-level league, while 15% were in a lower-level league but had more game appearances and minutes played than pre-injury. By 5 years 34% of athletes were playing in the same or higher-level league and 26% were in a lower-level league but had more game appearances and minutes played. At 2 years, there were no significant predictors of performance when evaluating factors such as concomitant injuries, undergoing surgery after ACLR, or mechanism of injury. However, the presence of a grade 3 or 4 chondral lesion at the time of surgery significantly impacted both career length and performance with only 15% of athletes playing at the same or higher league at 5 years and these athletes were 3.5 times more likely to be playing at a lower league level or retired (p=.029). Meniscus repair lengthened the RTP timeline (11.6 months versus 9.8 months, p=.001), but no impact was seen at 5 years with league level or performance (all p>.05). No other injury characteristic predicted performance at 5 years post ACLR. Conclusions: While a high level of return to play, 97%, was achieved in professional soccer players following primary ACLR, their performance decreased with time. Performance metrics show 59% of athletes are at the same league level at 2 years and this decreases to 34% at 5 years post ACLR. Presence of a Grade 3 or 4 chondral lesion significantly decreased performance metrics, while a meniscus repair delayed RTP but did not impact performance metrics at 5 years post ACLR.

Recently there has been increased focus on the medial collateral ligament (MCL) and the role the medial ligament complex plays in preventing valgus and external rotation, especially in the setting of a combined ligament injury. Multiple surgical techniques purport to reproduce "normal anatomy"; however, only one technique addresses the deep MCL fibers and the prevention of external rotation. Thus we describe the "short isometric construct" MCL reconstruction which is stiffer than the anatomic reconstructions. The "short isometric construct" technique resists valgus throughout range of motion whereas its obliquity resists tibial external rotation, helping to reduce the risk of anterior cruciate ligament graft re-rupture.

MRNA technology is not new, but with the COVID-19 pandemic, it is the first time it has been used on a large-scale basis in humans. The mRNA vaccines, BNT162b2 and mRNA-1273, have both demonstrated a high efficacy rate and acceptable safety profile which led to emergency approval. Nevertheless, there have been several news reports and some publications documenting the side effects of COVID-19 vaccination. Many of these side effects are known effects of other types of vaccinations and were documented in the vaccine trials.2Baden L.R. El Sahly H.M. Essink B. Kotloff K. Frey S. Novak R. et al.Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine.N Engl J Med. 2021; 384: 403-416https://doi.org/10.1056/NEJMoa2035389Crossref PubMed Scopus (3491) Google Scholar,10Polack F.P. Thomas S.J. Kitchin N. Absalon J. Gurtman A. Lockhart S. et al.Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine.N Engl J Med. 2020; 383: 2603-2615https://doi.org/10.1056/NEJMoa2034577Crossref PubMed Scopus (5352) Google Scholar However, there have been some novel side effects related to the modulation of the immune system. These include facial swelling in patients with a history of facial cosmetic dermal filler injections4Cirillo N. Reported orofacial adverse effects of COVID-19 vaccines: the knowns and the unknowns.J Oral Pathol Med. 2021; 50: 424-427https://doi.org/10.1111/jop.13165Crossref PubMed Scopus (35) Google Scholar and herpes zoster in patients with autoimmune inflammatory rheumatic diseases.5Furer V. Zisman D. Kibari A. Rimar D. Paran Y. Elkayam O. Herpes zoster following BNT162b2 mRNA COVID-19 vaccination in patients with autoimmune inflammatory rheumatic diseases: a case series.Rheumatology. 2021; (keab345. https://doi.org/10.1093/rheumatology/keab345): 1-6Google Scholar To date, there have been no publications describing musculoskeletal side effects. In this article, we present 4 shoulder cases that may have been impacted by mRNA vaccine administration. Of the 4 cases, 2 patients incurred a postoperative infection possibly related to vaccine administration, whereas the other two patients experienced functional loss related to vaccine administration. The first patient was a 58-year-old right-hand-dominant man who initially presented to our clinic 4.5 years before with a left shoulder rotator cuff tear. This injury was treated conservatively for 3.5 years until he underwent arthroscopic rotator cuff repair by the primary surgeon in March 2020, just before the COVID-19 pandemic. A double-row transosseous equivalent technique was used with 4.5-mm PEEK anchors in the medial row and 4.75-mm PEEK anchors in the lateral row. His postoperative course was unremarkable, and he had an excellent functional recovery. The patient presented with right shoulder pain in February 2021, which had worsened after a recent fall. A full-thickness supraspinatus tear was confirmed on magnetic resonance imaging (MRI) (Fig. 1). He underwent arthroscopic right shoulder rotator cuff repair in March 2021. An identical technique with the same anchor pattern as the prior surgery was used for the contralateral shoulder. At his first postoperative visit for the right shoulder on postoperative day (POD) 10, he commented that the postoperative pain in the right shoulder was much less than the postoperative pain experienced in the left shoulder the prior year. On POD 46, the patient contacted the office stating that he had been doing well until he received his second vaccination of the BNT162b2 mRNA vaccine on POD 38 in his left, not recently operated shoulder. He stated that soon after the vaccination, he started feeling fatigued and malaise with fever. He also noticed a significant increase of pain in the right arm, with redness and streaking distal to his right shoulder within two days of the vaccination. The malaise subsided after a few days, but the shoulder pain and discoloration symptoms worsened during this time. The patient returned to the clinic on POD 47. Peripheral laboratory values were drawn to assess for infection (Table I). He was sent for both MRI and a fluoroscopically guided aspiration of the shoulder joint. The aspirate yielded little fluid, mainly blood, but was still sent for analysis. The MRI demonstrated a large loculated fluid collection in the subacromial space with disruption of the rotator cuff repair and lucency around the previously placed anchors (Fig. 2).Table IPeripheral laboratory values for case #1 on POD 47.TestValueNormalWhite blood cell count (WBC)7.25.7-10.5Erythrocyte sedimentation rate (ESR)45∗Outside of normal range.0-15C reactive protein (CRP)2.2∗Outside of normal range.<.9POD, postoperative day.∗ Outside of normal range. Open table in a new tab POD, postoperative day. On POD 49, he underwent arthroscopic débridement with hardware removal. Operative findings included a failure of the rotator cuff repair. The anchors were loose because of the surrounding destruction of bone but were not displaced. There was moderate reactive bursitis, and the arthroscopy fluid was initially cloudy, but there was no gross purulence or efflux of fluid with placement of the trochar and cannula or with the initial visual assessment. During the procedure, cultures were obtained from the reactive bursitis. The sutures and anchors were removed and sent along with the cultures. Antibiotic treatment was not initiated until all cultures were obtained. A repeat arthroscopy and débridement were performed 2 days later. A peripherally inserted central catheter line was placed, and the patient was started on empiric antibiotics. The final Gram stain was negative. The cultures were held for 21 days and also remained negative. The patient was treated with 8 weeks of intravenous antibiotics for presumed Cutibacterium acnes. At 4 months after débridement and 8 weeks after conclusion of IV antibiotics, the patient underwent a revision rotator cuff repair, and postoperative recovery was unremarkable. The patient currently has little to no pain at 160 degrees of active elevation. The second case was a 68-year-old right-hand-dominant man with controlled type II diabetes. He has been followed by the primary surgeon for over 10 years for bilateral shoulder osteoarthritis. He underwent a right shoulder arthroscopic débridement with biceps surgery after 6 years of conservative treatment. He continued to have pain and presented for definitive shoulder arthroplasty 4 years later. He had not received any prior cortisone injections or invasive treatment to the shoulder since the arthroscopic procedure. A preoperative computed tomography scan was obtained to confirm the diagnosis and allow for templating for shoulder arthroplasty. He underwent routine right shoulder anatomic total shoulder arthroplasty in early March of 2021. His postoperative course initially was unremarkable. Prophylactic clindamycin had been given. He was also given 2 more doses while in the hospital. His serum glucose levels were well controlled while in the hospital. He was discharged home on POD 1. At his first postoperative visit on POD 14, he commented that his pain was surprisingly better than he thought it would be. He had some initial issues with constipation that had resolved, but otherwise unremarkable. The patient then called on POD 50, stating that he had developed some redness surrounding his incision. He explained that he was doing well until POD 25 when he received his second mRNA-1273 injection in his left (nonoperative) shoulder. He stated that he felt significant malaise after the injection for several days. He also noticed an almost immediate increase in his right shoulder pain at that time which had persisted. He had not been taking narcotics for several weeks, but he now needed narcotics to manage the pain. Examination of his wound demonstrated an apparent central abscess. A computed tomography scan was obtained looking for a deep abscess which was not identified. A fluoroscopically guided aspiration was also performed. Only 1 mL of bloody fluid was aspirated and was sent for culture and Gram stain. The peripheral laboratory values are in Table II.Table IIPeripheral laboratory values for case #2 on POD 50.TestValueNormalWhite blood cell count (WBC)8.25.7-10.5Erythrocyte sedimentation rate (ESR)50∗Outside of normal range.0-15C reactive protein (CRP)1.4∗Outside of normal range.<.9POD, postoperative day.∗ Outside of normal range. Open table in a new tab POD, postoperative day. The patient was then immediately taken to the operating room on POD 51 for open irrigation and débridement. It was noted to be superficial purulence which did track down to disrupt 30% of the subscapularis repair. There was no evidence of intra-articular purulence. More cultures were taken before antibiotic administration. The implants were well fixed and retained. A second open irrigation and débridement were performed on POD 53. The aspirate from POD 50 included testing for alpha defensin, which was positive. The cultures grew C acnes at 2 weeks after surgery, and oral antibiotics were prescribed. The patient completed the course of oral antibiotics at 6 months after surgery. At clinical follow-up, the patient had regained 130 degrees of active elevation and reported less pain in the surgical shoulder than the contralateral shoulder which also has known glenohumeral osteoarthritis. The third case was an 80-year-old right-hand-dominant man with a history of right anatomic shoulder arthroplasty in September 2018. At the time of surgery, a soft tissue mass was identified over his bicipital groove. It was completely removed and sent for pathology. He was diagnosed with lymphoma and underwent postoperative chemotherapy. Because of his treatment for the lymphoma, his last visit was in December 2018. At that time, he had 90 to 100 degrees of active forward elevation, and his pain was well controlled. He was not seen again until May of 2021. He stated that his shoulder was doing well until 6 weeks before, when he received the second dose of the BNT162b2 vaccination in his left, nonoperative arm. He subsequently developed shingles in his right upper extremity and face. In addition, he noticed that he lost the ability to raise his right arm. The shingles lesions had now resolved, but he was still unable to raise the arm, and he had significant pain in the shoulder. Active forward flexion was 0 with passive forward flexion to 120 degrees. He had significant deltoid atrophy on examination. An electromyography (EMG) had been ordered by another physician and was performed 3 days before his clinic visit, within 6 weeks of the onset of his symptoms. The results showed mild median, ulnar, and radial nerve neuropathy, whereas the axillary nerve showed normal function. An MRI ordered by an outside physician showed mild atrophy and fatty infiltration of the subscapularis and supraspinatus. The deltoid was difficult to assess because of signal artifact from the prosthesis. As of June 2021, he is being managed with physical therapy and will have a repeat EMG 3 months from the onset of his symptoms. He has been improving slowly from physical therapy and is gradually regaining active shoulder function. A 58-year-old right-hand-dominant woman presented with left shoulder pain in mid-May 2021. She received the first dose of the mRNA-1273 vaccine 33 days before her clinic visit, after which she developed immediate pain that worsened over time. She could no longer raise her shoulder, and she subsequently developed patches of numbness over her forearm. She does have a history of type II diabetes that is not well controlled. Her hemoglobin A1c was 13.0 two months before (normal <6.0). An MRI of the left shoulder performed 17 days after vaccination demonstrated a 30-mm paralabral cyst associated with the anterior glenoid labrum. She had no atrophy on physical examination but was hypersensitive to light touch over the arm and forearm. Active forward elevation was to 60 degrees. An EMG was performed which was consistent with left neuralgic amyotrophy (brachial plexitis or Parsonage-Turner syndrome). She is being treated currently with physical therapy. All surgeries have a risk of infection and other complications; however, the risk of infection for orthopedic cases is low. Specifically, infection after rotator cuff repair is very rare, with a reported prevalence of 0.006% to 3.4%.1Athwal G.S. Sperling J.W. Rispoli D.M. Cofield R.H. Deep infection after rotator cuff repair.J Shoulder Elbow Surg. 2007; 16: 306-311https://doi.org/10.1016/j.jse.2006.05.013Abstract Full Text Full Text PDF PubMed Scopus (130) Google Scholar,11Saltzman M.D. Marecek G.S. Edwards S.L. Kalainov D.M. Infection after shoulder surgery.Am Acad Orthop Surg. 2011; 19: 208-218https://doi.org/10.5435/00124635-201104000-00005Crossref PubMed Scopus (85) Google Scholar Systemic factors can influence the infection rate and include malnutrition, renal failure, liver failure, diabetes mellitus, chronic hypoxia, malignancy, immunodeficiency, immunosuppression, advanced age, tobacco use, and IV drug use.11Saltzman M.D. Marecek G.S. Edwards S.L. Kalainov D.M. Infection after shoulder surgery.Am Acad Orthop Surg. 2011; 19: 208-218https://doi.org/10.5435/00124635-201104000-00005Crossref PubMed Scopus (85) Google Scholar Comorbidities for case #1 are hypercholesterolemia and hypertension, but otherwise, the patient is healthy. He had undergone a prior rotator cuff repair of his left shoulder 1 year before with no complications. On the day of his right shoulder surgery, another patient with more comorbidities including diabetes also had a rotator cuff repair and has had no complications. The primary surgeon has had one prior rotator cuff repair infection in 18.5 years. This infection can certainly be explained statistically based on an expected infection rate of rotator cuff repair. However, the temporal association with the second vaccination is difficult to ignore. The risk of infection in primary shoulder arthroplasty is approximately 1%.12Singh J.A. Sperling J.W. Schleck C. Harmsen W.S. Cofield R.H. Periprosthetic infections after total shoulder arthroplasty: a 33-year perspective.J Shoulder Elbow Surg. 2012; 21: 1534-1541https://doi.org/10.1016/j.jse.2012.01.006Abstract Full Text Full Text PDF PubMed Scopus (202) Google Scholar The most common organism causing infection in total shoulder arthroplasty is C acnes, which accounts for approximately 39% of infections in shoulder arthroplasty.9Paxton E.S. Green A. Krueger V.S. Periprosthetic infections of the shoulder: diagnosis and management.J Am Acad Orthop Surg. 2019; 27: e935-e944https://doi.org/10.5435/JAAOS-D-18-00232Crossref PubMed Scopus (23) Google Scholar The risk factors of shoulder prosthetic joint infections include male sex, higher body mass index, and younger age at the time of the index procedure.9Paxton E.S. Green A. Krueger V.S. Periprosthetic infections of the shoulder: diagnosis and management.J Am Acad Orthop Surg. 2019; 27: e935-e944https://doi.org/10.5435/JAAOS-D-18-00232Crossref PubMed Scopus (23) Google Scholar Our case #2 has a history of well-controlled type II diabetes and no other risk factors. He had not received prior injections in the shoulder. Similar to the patient in case #1, he had little to no pain initially, but the pain significantly increased after a second mRNA injection for COVID-19. Another patient had a reverse shoulder arthroplasty on the same day as the index surgery and has had no complications. In addition, the primary surgeon has only had two primary arthroplasty infections in 18.5 years, which were both reverse arthroplasty for fracture cases. This is the first primary anatomic shoulder arthroplasty to present with infection. Similar to case #1, the temporal association with the second vaccination is difficult to ignore when evaluating case #2. The third case in this series developed shingles after mRNA vaccination. This adverse event has been reported by Furer et al in patients with autoimmune inflammatory rheumatic disease.5Furer V. Zisman D. Kibari A. Rimar D. Paran Y. Elkayam O. Herpes zoster following BNT162b2 mRNA COVID-19 vaccination in patients with autoimmune inflammatory rheumatic diseases: a case series.Rheumatology. 2021; (keab345. https://doi.org/10.1093/rheumatology/keab345): 1-6Google Scholar Case #3 is unique in that shingles resulted in profound loss of function in the shoulder that underwent arthroplasty over 2.5 years before. The patient has known severe glenohumeral osteoarthritis on the contralateral shoulder which received the vaccination but did not have any adverse events on that side. In addition, this patient has other comorbidities and has undergone prior chemotherapy and radiation therapy on the surgical shoulder, possibly adding to the increased risk for right-side involvement. In this case, the shingles occurred on the extremity that had prior radiation therapy. Nevertheless, this case illustrates that the mRNA vaccine may cause some type of modulation of the immune system that allows previously suppressed pathology to manifest itself. Patient #4 was diagnosed with neuralgic amyotrophy and had significant comorbidity with uncontrolled insulin-dependent diabetes mellitus. It is not clear if this played a role in her reaction to the vaccine, as uncontrolled diabetes is well known to adversely impact several other organ systems including the kidney, eyes, vascular system, and peripheral nervous system.6Jain N. Agarwal M. Steinberg H.O. Dagogo-Jack S. National trends and outcomes in patients with uncontrolled diabetes and related complications.Diabetes. 2018; 67: S1https://doi.org/10.2337/db18-190-LBCrossref PubMed Google Scholar In addition, this type of nervous system reaction is not necessarily specific to mRNA vaccines, but her presentation illustrates the concept that an mRNA vaccine can have an impact on the immune system, leading to complications. The 4 cases presented here represent possible musculoskeletal adverse events that will be evaluated in orthopedic clinics. These types of reactions are not unique to orthopedics, and anecdotal reports are beginning to be found in the literature. In a review of dermatologic reactions, McMahon et al reported 10 cases of shingles after the first or second dose of the mRNA vaccine.7McMahon D.E. Amerson E. Rosenbach M. Lipoff J.B. Moustafa D. Tyagi A. et al.Cutaneous reactions reported after Moderna and Pfizer COVID-19 vaccination: a registry-based study of 414 cases.J Am Acad Dermatol. 2021; 85: 46-55https://doi.org/10.1016/j.jaad.2021.03.092Abstract Full Text Full Text PDF PubMed Scopus (328) Google Scholar Shingles was considered a less common adverse event in the report of 414 adverse reactions which primarily included local cutaneous reactions. In a cohort of patients after cardiothoracic surgery, Merritt-Genore et al recommended that patients recover from surgery and postoperative complications before vaccination. The rationales were to allow a robust immune response to the vaccination and to avoid possible diagnostic confusion as to whether a symptom was a surgical complication or vaccine adverse event.8Merritt-Genore H. Moosdorf R. Gillaspie E. Lother S. Engelman D. Ahmed S. et al.Perioperative Coronavirus vaccination—Timing and implications: a guidance document.Ann Thorac Surg. 2021; 112: 1707-1715https://doi.org/10.1016/j.athoracsur.2021.07.016Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar Overall, there have been millions of mRNA vaccinations administered, and these types of adverse events are rare. However, orthopedic surgeons need to be aware of the possibility to better treat their patients. In the United States, approximately 300 million doses of the mRNA vaccines, BNT162b2 and mRNA-1273, have been administered as of June 2021.3Bloomberg More than 2.92 billion shots given: Covid-19 tracker [Internet].https://www.bloomberg.com/graphics/covid-vaccine-tracker-global-distribution/Google Scholar,13Statistica Number of COVID-19 vaccine doses administered in the United States as of June 27, 2021 by vaccine manufacturer [Internet].https://www.statista.com/statistics/1198516/covid-19-vaccinations-administered-us-by-company/Google Scholar Most of the individuals receiving the mRNA vaccines experience only minor and/or well-documented side effects. The cases presented here represent possible musculoskeletal adverse events that will be evaluated in orthopedic clinics. Fortunately, these cases are rare, but orthopedic surgeons need to be aware of this possibility to better treat their patients.

The anterior cruciate ligament (ACL) is a complex ribbon-like structure, which is approximately 3.5 times larger at the tibial and femoral insertions than at the midpoint. Accordingly, it is impossible to recreate with a single cylin-drical graft. However, this has not stopped surgeons from using the term "anatomic" to describe multiple ACL reconstruction techniques inserting at a number of different locations within the original ACL footprint, causing confusion. The term "anatomic" should be discarded and replaced by an anatomic description of the tunnel place-ments on the tibia and femur. Current ACL reconstruction techniques cite anatomical studies that identified "direct and indirect fibres" of the ACL. The "direct fibres" bear 85-95% of the load and provide the main resistance to both anterior tibial translation and internal rotation/pivot shift. On the femur, these fibres insert in a line just posterior to the intercondylar ridge and comprise the portion of the ACL that surgeons should strive to restore. Placement of the graft just posterior to the intercondylar ridge creates a line of placement options from the anteromedial bundle to the "central" position and finally to the posterolateral bundle position. The authors prefer placing the femoral tunnel in the isometric anteromedial position and addressing a high-grade pivot shift at the IT-band with a lateral extra -articular tenodesis. As with the femoral tunnel, the native ACL footprint on the tibia is much larger than the ACL graft and thus can be placed in multiple "anatomic" locations. The authors prefer placement of the tibial tunnel in the anterior most position of the native footprint that does not cause impingement in the femoral notch. Additional research is needed to determine the ideal tunnel positions on the femur and tibia and validating the technique with patient outcomes. However, this cannot be accomplished without describing tunnel placement with specific anatomical locations so other surgeons can replicate the technique.